Bascule-bridge.



VNo; 708,34af Patented sept. 2, |902. c. F. HALL.

AscuLE BRIDGE.

(Application filed Dec. 7. 1901.)

2 Sheets-Sheet I.

(No Model.)

n l Y f No. 708,348. Patented sept. 2, 1902.

c. F. HALL. BASCULE BRIDGE.

(Application filed Dec, 7. 1901.)

2 Sheets-Sheet 2,

(No Model.)

lliTllmilrml IIIIIIIIIIIIi THE wams mena co., Pnuaumo.. wnsmworoufn. c.

Nrrnn 'raras `Arn'r CHARLES r. HALL, or CI-IICAeo, ILLINOIS.

SPECIFICATION forming part of Letters Patent No. 708,348, dated september 2, 1902.

Application filed December 7, 1901. Serial No. 85,018. (No model.)

T0 @ZZ whom, it may concern:

Be it known that I, CHARLES F. HALL,a citizen ofthe United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Bascule-Bridge's, of which the following is a specification.

My invention relates to that class of lift or draw bridges commonly known as basculebridges, and has for its main object to dispense with the usual counterweight commonly employed in bridges of this class without at the same time increasing the extent of the inner or land section of the bridge or of the abutment or pier area in which it operates beyond that usually required in bridges of this class.`

A further object is to provide a bridge-span which shall be perfectly balanced or as nearly perfectly balanced as is practically possible in all positions which the span may assume between its extreme open and closed positions.

In an application heretofore iiled by me onA the 3d day of December, 1900, Serial No. 38,419, and renewed on the lst day of August, 1901, Serial No. 70,960, I set forth a type of bascule-bridge having as its salient novel feature a dry well provided with a concave scarp and a concave rear wall with which the under side and heel of the span cooperated, respectively, and in which the curved walls of the dry well were so relatedvto each other and to theline of movement of the center of gravity of the bridge-span as that the latter was in substantial equilibrium at all points in its travel without the employment of counterweights. My present invention embodies the same mechanical principle as that underlying my aforesaid application; but itembodies constructional details which study and experiment have demonstrated to constitute a superior practical embodiment of the generic mechanical and geometrical principle underlying my aforesaid application. In my present invention the heel of the bridge-span has a combined rearward and downward movement relatively to its fulcrum or axis of support, as inmy aforesaid application; but instead of guiding the heel of the bridge-span upon and in compression relatively to the concave rear wall of the dry well, as in the aforesaid application, I connect the heel of the bridge-span by a tension-link with a fixed pivotal point in the front wall of the dry well,

this point having a center about which the heel of the bridge-span swings in the arc of a circle. In the preferred form of my invention I also provide a series of fixed points of rolling contact on the supporting-abutment which engage a corresponding series of curved ways or tracks on the under side of :the bridge-spamthese points of rolling contact constituting a fulcrum-support and being preferably provided with positively-engaging gears for the purpose of operating the bridge-span by the simple rotation of its pivotal supports under conditions and circumstances in which the frictional contact between said parts might prove insuiiicient to effect such operation of the span.

My invention is illustrated in the accom- 'panying drawings, in which- Figure l is a side elevation, largely in the ,nature of a diagram, of a bascule-bridge span and its supporting-abutment, the latter being shown in vertical section. Fig. 2 is a side elevation of one of the pivotal supports of the span and its train of actuating-gears, the curved track or way of the span overlying the same being indicated in vertical section; and Fig. 3 is an end view of the parts shown in Fig. 2 looking at the same in the direction indicated by the arrow.

Referring to Fig. 1,the numeral 4 designates a vertically-operating bridge-span, and 5 is a suitable abutment or support therefor, having formed therein the usual dry well 6. Resting upon the inner pier of the abutment 5 is a rigid framework, (designated by 7,) which framework has journaled in its upper end a roller 8, the outer surface of which engages and cooperates with a curved way or track 9, formed on the under side of the bridge-span, and of alongitudinal extent corresponding, substantially, with the extent of longitudinal movement which the span undergoes in tilting from closed to open position, and vice versa. It will be understood that inpractice there will be a series of rollers S, disposed in transverse alinement and engaging a corresponding series of similarly-disposed curved ways or tracks on the bridge-span. For convenience of description, however, I refer to IOO - curved track 9 at the point of contact.

the cooperating elements of the bridge-span and its support in the singular, it being understood that these elements are duplicated on the opposite side of the bridge, and in some instances, as in the case of a span of nnusuallateral dimensions, may be employed at one or more points intermediate the lateral extremes of the span. 10 indicates a fixed point on the inner face of the wall or pier 5, which constitutes the geometricalcenter of a circle au arc of which lies between two points 11 and 12, denoting, respectively, the points occupied by the heel of the span in its closed and open positions, respectively. 13 designates a link pivoted at one end to the heel of the bridge-span at a point axially coincident with the point 11 and similarly pivoted at its opposite end in the inner face of the pier 5 at a point axially coincident with the point 10. The arm 18 thus becomes a radius for describing the arc of movement of the inner end or heel of the bridge-span between the open and closed positions of the latter. The center of gravity of the span in the opening and closing movements of the latter travels rearward in a substantially horizontal direction, and between this line and the curved line marking the track 9 and the arc 11 12, indicating the path of travel of the heel of the span, there exists a peculiar geometric relation whereby there is derived two resultant forces acting as supports for the mass of the span taken at the center of gravity, which resultants, disregarding external infinences-such as windage, expansion, and contraction, &c. hold poised in equilibrium the -mass at any point in its travel rearward, which equilibrium follows by reason of the fact that the direction of these resultants coincide, respectively, with the longitudinal axis of the link and with the normal to the The arc 11 12 and curved track 9 are placed in such relative positions that 'the link will be in tension and the load on roller 84 be from above and downward. of structure two desirable results follow, one of them being the avoidance of the necessity of counterweights, which require considerable space for their operation, and the other residing in the fact that the span can bei/operated with the application of a very slight power, such as is sufcient to merely disturb the balance of forces at all points between the open and closed position and to overcome the comparatively slight effect of extraneous iniiuences, above alluded to.

In Figs. 2 and 3 of the drawings I have illustrated in enlarged detail one form of operating mechanism, which is merely typical of a varity of forms which might be employed. In these views the supporting-rolleris shown at 8, carried in journal-bearings, preferably antifriction, 14 and 15 on either side thereof. It will be observed that the surface of the supporting-roller is smooth, except for the presence of a narrow circle of gear-teeth 8,

From this peculiarityA herein shown as located centrally of the roller. The engaging under surface of the track 9 is also formed smooth to overlie and ride upon the smooth surface of the roller, except that the central portion is provided with a longitudinal series of gear-pockets 9, adapted to coperate with the gear-teeth Sa. I wish it to be understood that in the practical embodiment of my invention the presence of the gear-teeth and the gear-pockets on the roller and track, respectively, is entirely optional. In many cases, especially those wherein the extraneous iuliuences are comparatively negligible, these features may be omitted, the rolling friction between the parts being amply sufficient to effect the operation of the span by the mere rotation of the roller. In other cases, especially those wherein the extraneous influences are of considerable moment, the presence of the gears and gear-pockets will be found desirable, if not necessary, to prevent slip between the parts in the operation of the span. Of course the gear elements of the roller and track might be formed the full width thereof, if desired, without departing from my invention. Owing to the substantially perfect balancing of the span at all positions, whereby the application of but a very slight power is required to operate it, plain smooth friction-surfaces on the roller and track will ordinarily be found sufficient. In order to employ a motor combining a high speed with a comparatively low horse-power, such as the electric motor indicated at 16, I provide a system of gearing therefrom to the roller whereby the power required is. geared down in approximately the ratio of sixty to one. In the particular arrangement of gearing shown it will be observed that the armature-shaft 17 of the motor drives a pinion 18, this pinion in turn driving agear 19 on a counter-shaft 20. On this latter is a pinion 21, enmeshing a gear 22, fast on an extended counter-shaft 23, the

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end of which latter is provided with a pinion 24E, engaging an overlying gear 25, fast on one end of a shaft 26, journaled in the supporting-frame beneath the roller 8. The opposite end of shaft 26 carries a pinion 27, which drives the gear 28, fast on anl overhanging end of the roller-shaft 29. By the arrangement of roller-driving mechanism described the motor itself and the supportingframe and its connections tothe roller may all be firmly and securely seated in and upon the pier 5 directly beneath the bridge-span.

In the embodiment of my invention herein illustrated and described I have shown the curved track relatively to which the fulcrumsupport has a sliding movement as formed upon the span itself, the fulcrum-point being stationary. It will be obvious that this ar; rangement might be simply reversed, as is the case in my prior application hereinbefore referred to, wherein the scarp or curbing of the bridge-abutment is provided with a downwardly and rearwardly curved convex face,

possessing the same characteristics and relation to the curve described by the heel of the span asthe curved track 9 herein shown,

while the roller is fixed relatively to the span instead of relatively to the underlying support, as in this case. Inasmuch as the same mechanical and geometrical principles are involved in the two arrangements, they are obviously the equivalents each of the other, and so far as this feature of my present invention is concerned I do not limit myself to the exact location and relative arrangement of the supporting-roller and its curved way or track as herein shown.

The operation of myiuventiou has already been clearly indicated from the foregoing description of its construction and capabilities. It will be evident thatthe center of gravity of the span is at all times and in all positions of the span so nearly in the vertical plane of the fulcrum or support that the "bridge is in substantial equilibrium at all times and points of its movement, and hence no counterbalance-weights are needed. The slight preponderance of gravity eifect on the bridge side of the fulcrum maintains a corresponding slight tensional effect through the link 13 upon the pivot lO; but this in connection with the peculiar character of the curve of the track or way 9 is insuflicientto in itself produce any relative slip between the track and its support by reason of the fact that the curve of the track is such as to afford at all times and points of the travel of the track over the rollera resisting plane which is normal to that slight component of gravity tend ing to produce a relatively sliding movement between the track and the roller. Hence the only power required to operate the span is practically such as is sufficient to overcome its normal tendency toward equilibrium, which power, it will be evident, is very small compared with the expenditure of power hitherto required to operate bridges of this type which depend upon the use of heavy counterweights and in which no attempt is made to preserve and maintain a substantial equilibrium at all points of movement of the span. To the extent that the power required to operate the span may be lessened, to that extent the economy of the structure is enhanced.

I claimm l. Inabascule-bridge,the combination with a vertically-swinging span, of an abutment supporting the weight of the same, contacting supporting-surfaces on the abutment and span respectively, having a sliding movement relatively to each other, and a pivoted tension-link connecting the heel of the span with a fixed point on the abutment, substantially as described.

2. Inabascule-bridge,the combination with a vertically-swinging span, of an abutment supporting the weight of the same, a way or track on one of said elements, a fulcrumroller journaled in or upon the other and contacting said way and having a relative travcling movement thereover, and a pivoted tension-link connecting the heel of the span with a ixed point on the abutment, substantially as described.

3. In abascule-bridge,the combination with a vertically-swinging span, of an abutment supporting the weight of the same, a fulcrumroller journaled in or upon the upper end of the abutment beneath the span, a way or track formed in or upon the span above and slidingly contacting said roller, and a tension-link pivoted at one end to the heel of the span and at its opposite end in the abutment, substantially as described.

Il. In abascule-bridge,the combination with a vertically-swinging span, of an abutment su pporting the Weight of the same, a fulcrumroller journaled in or upon the upper end of the abutment beneath the span, a way or track formed in or upon the span and overlying said roller, said way and roller having contacting friction-surfaces, means for rotating said roller, and a controlling device for the heel of the span, substantially as described. i

5. Inabasculebridge,thecombination with a vertically-swinging span, of an abutment supporting the weight of the same, a roller journaled in or upon the upper end of the abutment beneath the span, a tension-link pivot-ally connecting the heel of the span to the abutment, and a curved way or track on the span engaging the roller and so formed and located relatively to the center of gravity of the span and the arc of travel of its heel as that the span shall be in substantial equilibrium at all points of its movement, substan tially as described.

CHARLES F. HALL.

Witnesses:

SAMUEL N. POND, FREDERICK G. GOODWIN.

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